The present invention is related to log shaping machinery and more particularly to such machinery used to form substantially cylindrical logs as a construction material.
Natural wood logs are regaining popularity as a building material. Log homes have a special aesthetic appeal and can be energy efficient if properly constructed.
The insulative value of wood is not particularly high when values are measured through standard rectangular wooden boards. Logs, however, have a typical circular cross section that can lend a higher "R" value, depending upon the construction and type of wood. Conventional "R" values can vary not only with the thickness of wood, but also with its cross-sectional curvature. Annular rings and the cellular content of the wood add insulative qualities to the overall wood thickness. Escaping heat is trapped at successive circular barriers formed by the annular rings and within the tiny open cellular structure of the wood grain. The circular cross-sectional configuration of the logs forming a structure wall is therefore a very desirable feature.
One prevalent problem with log construction has been the requirement of properly fitting logs together to obtain continuous, closed joints along their full length. Logs have a natural taper from one end to the other. Log taper can partially be corrected in construction by reversing lengths (end-for-end) of successive logs as the wall is being constructed. This technique, however, only solves the problem where tapers are nearly identical. Ideally, logs should be perfectly round, both for proper insulation value and for highest structural stability.
It therefore becomes desirable to obtain a machine that will automatically form logs accurately with surfaces that are substantially cylindrical and centered about their longitudinal axes. The individual logs should be of uniform diameter to facilitate uniform construction of structural walls and to provide uniform insulative capacity.